As shown in, for example, the patent document 1, a conventional liquid material vaporization apparatus comprises a main body block heated by a heater, inside of which arranged are a gas-liquid mixing section where a liquid material and a carrier gas are mixed, a liquid material introduction path to introduce the liquid material into the gas-liquid mixing section, a carrier gas introduction path to introduce the carrier gas into the gas-liquid mixing section, a vaporization nozzle section to subject a mixture of the liquid material and the carrier gas to flash boiling, and a mixed gas derivation path to derive the mixed gas vaporized by the vaporization nozzle section.
Since a flow rate of the carrier gas directly affects a partial pressure of the liquid material in the mixture, the flow rate of the carrier gas is an important factor to determine a vaporized amount of the liquid material.
However, in the arrangement of the above-mentioned conventional liquid material vaporization apparatus, all of the introduced carrier gas passes the vaporization nozzle section. With this arrangement, there is a problem in that a pressure loss of the carrier gas in the vaporization nozzle section becomes big so that the flow rate of the carrier gas is restricted. As a result, there is a problem in that the vaporized amount of the liquid material is restricted.
In addition, it can be simply conceived that a nozzle shape (a nozzle diameter) of the vaporization nozzle section is changed so as to increase the flow rate of the carrier gas, however, there is a problem in that the nozzle shape is difficult to change because the nozzle shape largely affects the vaporization efficiency.    Patent document 1: Japan patent laid-open number 2004-31441